Buffalograss, Buchloe dactyloides (Nutt) Engelm., is recognized to be a warm-season stoloniferous, sod-forming, perennial grass. It is a drought tolerant and an important range grass found mainly in the central prairies of the United States with its full range of distribution extending from Canada to Mexico (U.S. Agriculture Handbook, 1959). The buffalograss is the only species of its genus. It contains diploid, tetraploid, and hexaploid races (Stebbins, 1975), of which only the latter occur in the Great Plains area.
The diploid race mainly occurs in Central Mexico and southern Texas (Reeder, 1971) and it has only recently been researched for economic values, especially for turfgrass development. Genetic variation in shade, cold, and salinity tolerance has been detected among buffalograss germplasm collections (Wu and Lin, 1994, 1996; Wu and Harivandi, 1995). Allelochemical compounds found in buffalograss function as a broad-spectrum preemergence herbicide. Accordingly, they are potentially useful traits for buffalograss breeding (Wu et al., 1997).
The new cultivar of the present invention is a vegetatively propagated, drought resistant female buffalograss clone resulting from mass selection. Seeds of diploid buffalograss germplasms were collected from locations in Mexico including San Jose, San Clayetano, and Venegas. The population sizes of the three population were 215 from San Jose, 250 from San Clayetano and 300 from Venegas. Plants were established from the seeds and these were space planted during 1987 in an experimental field at the University of California, located at Davis, Calif., U.S.A. The plants were mowed on a weekly basis at a two-inch height during the growing season from May to the end of October.
Individual clones were selected for rapid vegetative growth, high turf density, and extended winter turf green coloration. Approximately 80 percent of the plants were eliminated during this selection for the above characteristics. The remaining plants were subjected to drought stress by terminating irrigation during the following summer months for a period of eight weeks from June 15th to August 18th. Two male plants and two female plants were selected from each of the three populations on the basis of their superior performance. The six male and six female clones were grown close together in the field to achieve mass crossing and the resulting seeds were harvested from the female plants. These seeds were germinated in the greenhouse and grown for six weeks before being transplanted into the field. Approximately six hundred plants were space planted in the field and were subjected to turfgrass management. More specifically, the plants were mowed weekly to a height of 2 inches, were irrigated every 10 days, and in April and in August one pound of nitrogen was applied per 1000 square feet as ammonium sulfate. Two clones from this planting previously were selected and were released. These were the xe2x80x98Hilite 15xe2x80x99 cultivar (U.S. Plant Pat. No. 8,896) and the xe2x80x98Hilite 25xe2x80x99 cultivar (U.S. Plant Pat. No. 8,897). The new cultivar of the present invention additionally was studied and evaluated and was selected and carefully preserved as a result of its exhibited combination of characteristics.
It was found that the new diploid female buffalograss cultivar of the present invention exhibits:
(a) stolons of fine texture,
(b) superior drought tolerance,
(c) a competitive growth habit,
(d) short winter dormancy
(e) superior turf green color retention, and
(f ) high turf density with a rapid stolon spreading rate and short plant height that provides a low maintenance quality turf.
The new cultivar of the present invention can be readily distinguished from the xe2x80x98Hilite 15xe2x80x99 and xe2x80x98Hilite 25xe2x80x99 cultivars by shorter and thinner internodes, fewer burrs per spikelet, smaller burrs, and fewer flowers per burr. As reported hereafter, under field management conditions at Davis and Riverside, Calif., U.S.A., a superior turf quality was displayed over the entire growing season by the new cultivar of the present invention. Also, a greater vegetative spreading rate, a higher turf density, greater injury regrowth potential, greater shade tolerance, and better turf green color retention in the fall have been displayed by the new cultivar. A greater dry weight allocation in the vegetative growth and a lesser weight allocation in the sexual reproductive parts have been displayed by the new cultivar.
The new cultivar of the present invention has been vegetatively propagated by the use of stolons, sprigs, and plugs. Such asexual propagation was carried out initially in greenhouses at the Department of Environmental Horticulture, University of California, located at Davis, Calif., U.S.A. Thereafter vegetative propagation has been carried out at Riverside, and near Anaheim, Calif., U.S.A. Such propagation has confirmed that the characteristics of the new cultivar are stable and are reliably transmitted to subsequent generations.
The new cultivar of the present invention has been named xe2x80x98UCD-95xe2x80x99.